ENERGY-DEPENDENCE OF C-60-GRAPHITE SURFACE COLLISIONS

The resilience of C-60 fullerene with graphite (0001) surfaces has bee n investigated by means of molecular dynamics simulations with empiric al model potentials. The initial energy of C-60 ranges from 30 to 300 eV. It is shown that when the impact energy is above 60 eV, the reboun ding energy of C-60 is nearly independent of the impact energy. The sc attering is highly inelastic and the internal excitation energy of the scattered molecule increases with the incident energy. These results are consistent with experiment. Furthermore, the simulations provide i nsight into the microscopic aspects of the scattering. The rebounding processes at different energies are found to exhibit similar dynamic b ehavior and the molecular center-of-mass motion can be regarded as mov ing in a quadratic harmonic potential. All of these results support a schematic picture to describe nonreactive C-60-surface collisions. (C) 1998 American Institute of Physics.